In 2019,Nature (London, United Kingdom) included an article by Xiang, Jinbao; Shang, Ming; Kawamata, Yu; Lundberg, Helena; Reisberg, Solomon H.; Chen, Miao; Mykhailiuk, Pavel; Beutner, Gregory; Collins, Michael R.; Davies, Alyn; Del Bel, Matthew; Gallego, Gary M.; Spangler, Jillian E.; Starr, Jeremy; Yang, Shouliang; Blackmond, Donna G.; Baran, Phil S.. Reference of tert-Butyl 4-hydroxypiperidine-1-carboxylate. The article was titled 《Hindered dialkyl ether synthesis with electrogenerated carbocations》. The information in the text is summarized as follows:
Hindered ethers are of high value for various applications; however, they remain an underexplored area of chem. space because they are difficult to synthesize via conventional reactions. Such motifs are highly coveted in medicinal chem., because extensive substitution about the ether bond prevents unwanted metabolic processes that can lead to rapid degradation in vivo. Here we report a simple route towards the synthesis of hindered ethers, in which electrochem. oxidation is used to liberate high-energy carbocations from simple carboxylic acids. These reactive carbocation intermediates, which are generated with low electrochem. potentials, capture an alc. donor under non-acidic conditions; this enables the formation of a range of ethers (more than 80 have been prepared here) that would otherwise be difficult to access. The carbocations can also be intercepted by simple nucleophiles, leading to the formation of hindered alcs. and even alkyl fluorides. This method was evaluated for its ability to circumvent the synthetic bottlenecks encountered in the preparation of 12 chem. scaffolds, leading to higher yields of the required products, in addition to substantial reductions in the number of steps and the amount of labor required to prepare them. The use of mol. probes and the results of kinetic studies support the proposed mechanism and the role of additives under the conditions examined The reaction manifold that we report here demonstrates the power of electrochem. to access highly reactive intermediates under mild conditions and, in turn, the substantial improvements in efficiency that can be achieved with these otherwise-inaccessible intermediates. In the experiment, the researchers used tert-Butyl 4-hydroxypiperidine-1-carboxylate(cas: 109384-19-2Reference of tert-Butyl 4-hydroxypiperidine-1-carboxylate)
tert-Butyl 4-hydroxypiperidine-1-carboxylate(cas:109384-19-2) is a 4-hydroxypyridine with a boc protecting group used in the preparation of neurologically active agents and other pharmaceutical compounds.Reference of tert-Butyl 4-hydroxypiperidine-1-carboxylate
Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem